1、 gravity
2、 He could hardly keep his gravity、他忍不住要笑出來(lái)。
3、 Anything that is dropped falls towards the centre of the earth because of the pull of gravity、物體脫手即向地心方向跌落是由于重力吸引的緣故。
4、 The stone rolled down the hill by gravity、石頭在重力作用下向山下滾去。
5、 She does not know the gravity of her illness、她不知道自己病情嚴重。